Filewise backup applications need two features which until now have been mutually exclusive. First, for the base filesystem backup (i.e. base backup) and all of the incremental filesystem backups (i.e. incremental backups), being able to present a full mirror image of each backup individually is desired. At the time of the incremental backup, the incremental backup is a current filesystem backup. Second, being able to conserve space on the backup media (a) by not creating duplicate directory structures for each backup and (b) by not storing duplicate files more than once, is also desired. These two features continue to be mutually exclusive in prior art filewise backup applications.